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D. EV,ANS.. Steam Pump.

No. 242,440. Patented June 1188!.

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D. EVANS. Steam Pump.

No. 242,440. Patented June 7,1881.

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N. FETERS. PhMWUXhogmpher. Washinflnn. D. Q

NITED STATES PATENT OFFICE.

DAVID EVANS, OF OONNELLSVILLE, PENNSYLVANIA, ASSIGNOR TO BOYTS, PORTER 85 00., ()F SAME PLACE.

STEAM-PUMP.

SPECIFICATION forming part of Letters Patent No. 242,440, dated June 7', 1881.

Application filed March 16, 1881.

To all whom it may concern Be it known that I, DAVID EVANS, a citizen of the United States,residingat Gonnellsville, in the county of Fayette and State of Pennsylvania, have invented new and useful Improvements in Steam-Pumps, of which the following is a specification.

I have improved the steam pumping-engine to effect certain advantages and results in the 10 valve movement by means of an oscillating flat-faced valve attachment arranged within the side of an auxiliary valve-chest and operatin g the slide-valve by a double-ended pistonvalve arranged within a main valve-chest and communicating with the oscillating flat-faced valve. The oscillating flat-faced valve is operated from the pump piston-rod by suitable mechanism, and the said oscillating flat-faced valve has a balanced action.

Referring; to the drawings, Figure l represents a partial vertical longitudinal section of a steam pumping-engine embracing my improvements; Fig. 2, a vertical cross-seclion taken through the oscillating flat-faced valve attachment. Fig.3is theauxiliarysteam-chest for the oscillating flat-faced valve Fig. 4, an elevation showing the connection for operating the oscillating flat-faced valve attachment.

Fig. 5 is a top view of the valve-scat.

The steam-cylinder A has an ordinary piston, B, connected by a piston-rod, b, to the pump-piston.

On the cylinder A is secured the steam-chest O, in which moves the piston-valve D, having 5 a head, (I d, at each end, and between them the slide-valve E (of D form) is connected to the piston-valve by an upward projection, c. The slide-valve is supplied with the ordinary exhaust-cavity, and moves on the valve-face of the cylinder, through which the steam-inlet and exhaust ports lead to the interior of the cylinder. These ports a a are each provided with auxiliary or branch ports 0 c, and the usualeXhaust-port, f,is arranged in the center.

In the branch ports suitable plug-valves may be arranged to close or regulate the ports or openings.

On one side of the main steam-chestG is arranged an auxiliary steam-chest, F, of circular form, and having a flat face, upon which an os- (No model.)

cillating flat valve, G, moves. This valve is made of semicircular or circular form, and is provided at its rear side with a cavity, g, while on its opposite side a stem, 9, is attached, which passes through a suitable stufling-box on the back or cover F ofsteam-chest F. The valve fits against the cover of the chest, as well as the val ve-seat, and th us forms a groundjoint, but may have springs arranged on its stem to force or hold the valve to its seat, if desired. In the seat of this valve chest are arranged two ports, h h, through which the steam is alternately admitted lothe main chest and valve as it is oscillated.

To the cover of the chest F is secured a lug, it", which serves as a guide for the valve stem or rod H. This stem is provided with gibs l, which alternately strike againsta pendent arm,

I, secured to the stem of the valve G, and thus move it in opposite directions,and admit the steam to the outer ends of the valve pistonheads.

A small hole, t, is drilled in the seat or chest F through to the main chest, to admit steam to the space between the two piston-heads of the main valve, and from here it is admitted and exhausted by the D slide-valve to and from the main cylinder.

The valve-stem H is connected at its opposite cnd to an arm, K, on the cross-headL,whicl1 is secured to the piston-rod,and it is guided by a guide, M, attached to the steam and pump cylinders. The piston-valve is provided with a stem projecting at one end through the head of the chest, by which it can be adjusted, and does not require any packing.

The auxiliary chest is bored out and faced off on the inner side for the oscillating-valve seat, and said valve is ground off on both sides inside to fit said seat, and outside to fit the head, so that there shall be no endplay to said valve, and in akingabalanced valve. This valve is also turned off at the circumference to fit in side of the auxiliary chest.

The advantages of my valve attachment are, 5 th at the oscillating valve, having aflat face and moving against flat surfaces, forms a balanced valve, allowing the valve to work free when under pressure; or the valve can be used without admitting any steam to it. Moreover, mo

it is not liable to get out of order, as it is very simple in construction, avoiding tappets or other valve-gear, as well as auxiliary slidevalves. It moves very little in either direction, and, of course, wears very little, as well on its faces as on the stem. All its parts are easily accessible, and no steam-pressure is required to keep the valve against the seat. It I has no dead-centers, and can be started or stopped at any point of its stroke.

In using the pump under heavy pressure, steam is not admitted to oscillating valve. \Vhen the oscillating valve opens the port at one end of piston-valve it frees that end, and, there being no packing'on the piston-valve, the steam passes over the other end of pistonvalve and causes valve to move to the other end, that is free. In using the oscillating valve in this way I leave space between valve and head, and slip a spiral spring over stem on valve, the spring setting valve against seat. In this way the oscillating valve works free under any pressure.

The operation is as follows: Steamis admitted to the auxiliary chest, and through the small hole 2' to the main steam-chest, and as the tlat valve oscillates and uncovers the ports h h the steam passes alternately to outer ends of the piston-valve heads (I d and moves the piston-valve and D-valve with it in opposite directions. The steam then passes from the space between the piston-heads, through the regular steam-ports a a, into the main cylin der as the ports are alternately uncovered by the slide-valve E, which is moved, of course, by the two piston-heads, which, are moved only by steam-pressure, and without outside tappets on valve-gear.

By arranging the branch ports 0 c as shown a steanrcushion is formed in the cylinder to prevent shocks, and giving a steady movement of the engine and pump. The steam is exhausted through the exhaust-cavity of the D'valve and central exhaust-port, f, into the atmosphere.

In a circular form of oscillating valve no steam is used on said valve, but depends on the exhaust. \Vhen steam is used on such valve small holes are drilled in its face to admit steam to ports.

It is important that the ports h h in the valve-seat F should be oblong, and be arranged in horizontal relation to each other, as shown in Fig. 3, so as to cause the slide-valve E to open the whole length of the port at once, and thereby allow the pump to run very slow and still change its stroke properly.

The shape of the cavity g in the valve G is made to suit the ports in the seat.

I claim- 1. In a single-cylinder steam pumping-engine, an oscillating flat valve arranged in an auxiliary steam-chest formed upon one side of the main steam-chest, and having direct com munication with it, substantially as and for the purpose specified.

2 In a steam pumping-engine, an oscillating flat valve arranged in an auxiliary steamchest formed upon one side of the main steamchest, and having direct communication with it, in combination with a piston-valve and the steam-cylinder A, substantially as and for the purpose set forth.

3. In a siuglecylinder steam ptnnping-engine, an oscillating fiat valve arranged in an auxiliary steam-chest formed upon one side of the main steam-chest, the seat ofsaid valve having the oblong ports h h, whereby to cause the slide-valve E to be operated so as to cause it to open the whole length of the port at once, substantially as described, for the purpose specified.

4. In a steam pumping-engine, the combination of the flat oscillating valve G, provided with a stem, g, and pendent arm I, with the rod H, having gibs l l, and the fixed guide It for said rod, all constructed and arranged substantially as specified.

-5. In a steam pumping-engine, the combination, with the slidc-valve E and its steammoved piston, having piston-heads at each end and arranged in relation to such valve, substantially as described,olan oscillating flat valve provided with a face recess, and arranged in an auxiliary steam-chest communicating with the main steam-chest, substalr tially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

DAVID EVANS.

\Vitnesses WV. 1. REID, A. A. H001). 

